[BUG] getter Method is not correct in generated model

When generating a client library, the getters for a field is getBigDecimal() and its return type is BigDecimal but there is no import for BigDecimal data type.
So, when i am using type-mappings then return type is changed to fully qualified class name and getters method is also changed to getjava.math.BigDecimal() . (getter method should not have changed )

public java.math.BigDecimal getjava.math.BigDecimal() throws ClassCastException {
return (java.math.BigDecimal)super.getActualInstance();
}

--type-mappings BigDecimal=java.math.BigDecimal

i tried using import-mappings but generator is not adding import for BigDecimal.
--import-mappings BigDecimal=java.math.BigDecimal

openapi-generator version - 6.2.0
Library - jersey2

OpenAPI declaration file content :

Command line used for generation

As per naming conventions, this is wrong 👍
https://stackoverflow.com/questions/2948083/naming-convention-for-getters-setters-in-java

Reproduce generation for the reported OpenAPI declaration with the jersey2 library, using the BigDecimal type-mappings and import-mappings options. Inspect the generated model getter and imports; done means the getter remains getBigDecimal(), returns java.math.BigDecimal, and the generated Java code has the required import or valid fully qualified type usage.